Project Summary/Abstract Lead-PI: Timothy Clark University of San Diego Sub-PI: Gregory O'Neil Western Washington University Title: Nucleophilic borylation of aldehydes and conjugated carbonyls: Applications to homologation and carbosilylation reactions Abstract: The proposed research involves the development of synthetic methods that utilize the copper- catalyzed nucleophilic borylation of aldehydes and ?,?-unsaturated carbonyls. The resulting organoboronate esters will be used as intermediates in two types of synthetic reactions: (1) homologation of the carbon?boron bond with complex homologating agents; (2) oxidation to set up intramolecular carbosilylations to form tertiary alcohols stereoselectively. These two approaches to preparing synthetically useful and highly-substituted organic intermediates will simplify access to a number of biologically relevant targets. The versatility and selectivities afforded by these new methods will prove superior for a number of synthetic applications. The two major aims of this project are: 1. Utilize aldehyde borylation/homologations to construct highly-substituted organoboronate esters with contiguous stereocenters. 2. Develop intramolecular carbosilylations of ?-hydroxyketones using tethered silanes.